Modeling GPR radiation and reflection characteristics for a complex temperate glacier bed

We demonstrate that ground penetrating radar (GPR) reflection data from a temperate glacier are accurately modeled using a Helmholtz‐Kirchhoff diffraction integration technique that incorporates the radiation characteristics of point dipoles on a half‐space interface. This is accomplished by comparing field data to simulated data. Our 40‐MHz field data are from a 100 × 340 m (x‐ and y‐dimensions, respectively) survey grid containing 51 parallel survey lines. The field data were collected with the dipole oriented perpendicular to the survey line (x‐dipole). The synthetic data used isotropic, x‐dipole, and y‐dipole antennas, and reflections were calculated using a bed topography previously defined by 3D Kirchhoff migration. The comparisons between the real and synthetic waveforms show excellent agreement, including reflection arrival times, amplitude trends, interference patterns, and false layering from out‐of‐plane reflections. The location of reflectors determined from exploding reflector rays explains t...